Rotational atherectomy system with enhanced distal protection capability and method of use

ABSTRACT

An atherectomy system for removing a stenotic lesion from within a vessel of a patient is disclosed. The system comprising an atherectomy device for reducing the lesion and a separate elongate drainage catheter for evacuating from the treated vessel embolic particles released into the vessel from the stenotic lesion during its reduction by the atherectomy device during an atherectomy procedure. The atherectomy device and the separate elongate drainage catheter are each configured for introduction into the patent&#39;s vasculature though separate openings in at least one peripheral artery of the patient.

The present invention relates to a rotational atherectomy system forremoving a stenotic lesion from within a vessel of a patient. Morespecifically, the invention relates to a rotational atherectomy systemwith enhanced distal protection capability for removing or reducingstenotic lesion in a human artery by rotating an abrasive element withinthe artery to partially or completely ablate the stenotic lesion andsimultaneously remove out of the patient's body abraded particles(embolic particles or debris) released into the treated artery duringthe rotational athererctomy procedure. It should be understood thatrotational atherectomy devices and rotational athererctomy proceduresare often referred to as rotational angioplasty devices and rotationalangioplasty procedures. One type of rotational atherectomy devices isreferred to as an orbital atherectomy device. All these terms may beused interchangeably herein.

Atherosclerosis, the clogging of arteries, is a leading cause ofcoronary heart disease. Blood flow through the peripheral arteries(e.g., carotid, femoral, renal, etc.), is similarly affected by thedevelopment of atherosclerotic blockages. One conventional method ofremoving or reducing blockages in blood vessels is known as rotationalatherectomy. A device and a method for performing the RotationalAtherectomy Procedure are known from U.S. Pat. No. 4,990,134 to Auth. Arotational atherectomy (angioplasty) device based on this patent iscommercially available from Boston Scientific Corporation of Natik,Mass., USA.

The distal end portion of this prior art device is shown in FIG. 1. Theabrasive burr 1 of this Auth device is attached to a distal end of ahollow flexible drive shaft 2. The abrasive surface of the burr isformed from diamond particles 3. The device is rotated around a specialguidewire 4, which is advanced across the stenotic lesion. The device isadvanced towards the stenotic lesion around (over) the guidewire. Theabrasive burr is positioned against the occlusion and the drive shaft isrotated around the guidewire at extremely high speeds (e.g.,20,000-160,000 rpm). As the abrasive burr rotates, the physicianrepeatedly advances it towards the stenotic lesion so that the abrasivesurface of the burr scrapes against the occluding tissue anddisintegrates it, reducing the occlusion and improving the blood flowthrough the vessel. It should be understood that the terms abrasive burrand abrasive element may be used interchangeably herein.

U.S. Pat. No. 6,132,444 to Shturman (the instant inventor) et al.,describes a rotational atherectomy device comprising an abrasive element11 which is located proximal to and spaced away from a distal end of thedrive shaft 12. This abrasive element is formed from diamond particles13 directly electroplated to wire turns 14 of an enlarged diameterportion 15 of the drive shaft 12. The enlarged diameter portion 15 ofthe drive shaft is asymmetric and is responsible for providing anabrasive element with a centre of mass which is spaced away from therotational axis of the drive shaft. The device is rotated around aspecial guidewire 4 and its eccentric abrasive element 11 is able toopen the treated stenotic lesion to a diameter substantially larger thanthe maximum diameter of the abrasive element.

FIG. 3 shows a side sectional view of the distal end portion of a thirdembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 3 is similar to the device of FIG. 2 except that theabrasive element comprises a prefabricated abrasive crown 16 disposedaround the eccentric enlarged diameter portion 15′ of the drive shaft12′. The prefabricated abrasive crown 16 is known from U.S. patentapplication Ser. No. 10/272,164 to Shturman (the instant inventor). Theprefabricated abrasive crown 16 is formed from the diamond particles 13′bonded to a metallic sleeve 17 rather than directly to wire turns 14′ ofthe drive shaft 12′. The device is rotated around a special guidewire 4,and it is commercially produced by Cardiovascular Systems, Inc. ofMinnesota, USA.

FIG. 4 illustrates in longitudinal cross-section operation of arotational atherectomy device known from WO 2006/126176 to Shturman (thecurrent inventor). The rotational atherectomy device (of FIG. 4)comprises a solid eccentric abrasive element and two solid asymmetricsupport elements 20D, 20P mounted on a hollow flexible drive shaft 21.The solid asymmetric support elements 20D, 20P have their centres ofmass spaced away (offset) from a rotational (longitudinal) axis of thedrive shaft 21 and, during rotation of the drive shaft, act ascounterweights to the eccentric abrasive element 33. Preferably, therotational atherectomy device includes a distal solid counterweight 20Dlocated on the drive shaft 21 distal to and spaced away from theabrasive element 33 and, a proximal solid counterweight 20P located onthe drive shaft 21 proximal to and spaced away from the abrasive element33. In the most preferred embodiment of the invention, the centre ofmass of each of the solid counterweights is separated from the centre ofmass of the abrasive element by an angle of 180 degrees around the axisof the drive shaft. When the drive shaft of the rotational atherectomydevice with solid counterweights is rotated, centrifugal forcesgenerated by the solid counterweights 20D, 20P and the eccentricabrasive element 33 preferably act in substantially the same plane butin opposite directions. These centrifugal forces cause the distal endportion of the drive shaft to flex and assume a generally bowed orarcuate shape. During rotation of the drive shaft, the abrasive elementand each of two solid counterweights move in orbital fashions around theaxis of rotation of the drive shaft in orbits that are substantiallylarger than the respective diameters of the abrasive element or solidcounterweights.

The method of use of the device preferably includes the step ofpartially withdrawing the guidewire 4′ into the lumen of the drive shaftsuch that the distal end of the guidewire 4′ is located within the lumenof the drive shaft 21 proximal to the distal end portion of the driveshaft. Pressure applied by the abrasive element and the solidcounterweights to the tissue to be removed or to the inner surface ofthe vessel wall can be easily controlled by adjusting the rotationalspeed of the drive shaft (i.e. the faster the speed of rotation, thegreater the applied pressure), as well as by selecting the respectiveweights of the abrasive element and solid counterweights. It should benoted that the eccentric disposition of the abrasive element and solidcounterweights is not limited to their geometrical eccentric positionbut, much more importantly, involves the eccentric disposition of theircenters of mass with respect to the rotational axis of the drive shaft.

It should be understood that the terms ‘solid counterweight’, ‘solidasymmetric support element’ and ‘solid support element with a centre ofmass offset from a rotational axis of the drive shaft’ are usedinterchangeably throughout the specification.

FIG. 5 illustrates in longitudinal cross-section operation of a fifthembodiment of the rotational atherectomy device of the prior art. Thisrotational atherectomy device is known from WO 2006/126175 to Shturman(the current inventor) The rotational atherectomy device (of FIG. 5)comprises a solid abrasive element 35 and two solid support elements22D, 22P mounted on a hollow flexible drive shaft 21′. The device ofFIG. 5 is similar to the device of FIG. 4 except that the solid abrasiveelement 35 and the solid support elements 22D, 22P are symmetric withrespect to a rotational (longitudinal) axis of the drive shaft 21′ (i.e.they have their centres of mass lying on (the) a rotational(longitudinal) axis of the drive shaft 21′. FIG. 5 illustrates operationof the device in a curved vessel. The device is rotated around a specialguidewire 4′ which has to be withdrawn into the drive shaft 21′ prior tostarting its rotation.

In all of the prior art rotational atherectomy devices such as describedabove with reference to FIGS. 1 to 5, an elongated drive shaft isrotatable around a stationary guidewire. A long proximal portion of thedrive shaft is rotatable within an elongated stationary drive shaftsheath 24, said drive shaft sheath 24 forming an annular lumen betweenthe stationary sheath and the rotatable drive shaft. A saline solutionor special lubricating fluid is pumped into the annular lumen betweenthe stationary sheath and the rotatable drive shaft. A portion of saidsaline solution or special lubricating fluid is able to pass betweenadjacent wire turns of the drive shaft into a second annular lumenformed between the drive shaft and the guidewire thereby reducingfriction between the drive shaft and the guidewire. In all of the priorart rotational atherectomy devices referred to above the antegradeflowing saline solution ‘FF’ or special lubricating fluid enters thetreated vessel from a (the) distal end of the stationary drive shaftsheath 24 and thereby entrains and propels distally in an antegradedirection ‘FF’ along the treated vessel 100 embolic particles (debris)abraded by the abrasive element. The distal migration of the embolicparticles along the treated vessel and potential embolisation of verysmall diameter arteries or capillaries by the embolic particles is ofmajor concern to physicians who practice in this field. Potentiallylife-threatening complications which may be caused by the embolicparticles produced during the rotational atherectomy procedure preventuse of the above described rotational atherectomy devices for treatmentof stenotic lesions in the carotid arteries.

Currently, several types of filter based distal embolic protectiondevices (EPDs) are commercially available for use during balloonangioplasty procedures. These devices are designed to prevent migrationof embolic particles larger than 100 microns and cannot preventmigration of very small embolic particles produced during rotationalatherectomy procedure. One concept of providing a rotational atherectomydevice with distal embolic protection capability is known from U.S. Pat.No. 5,681,336 (to Clement et al.). According to this concept, migrationof abraded embolic particles along the treated artery is prevented bytemporarily occluding the treated artery distal to the stenotic lesionand aspirating abraded particles from the treated artery prior todeflating a guidewire mounted occlusion balloon. The rotationalatherectomy device known from U.S. Pat. No. 5,681,336 (to Clement etal.) has a complicated construction and is difficult to manufacture on acommercial scale.

Disadvantages associated with either limited or completely absent distalembolic protection of all commercially available rotational atherectomydevices have been addressed in WO 2006/126076 to Shturman (the instantinventor). In accordance with WO 2006/126076 every rotationalatherectomy device of the prior art described below and shown in FIGS. 6to 16C differs from the devices of the prior art described above andshown in FIGS. 1 to 5 in that its drive shaft has a fluid impermeablewall and allows an antegrade flow FF of pressurised fluid through alumen of the drive shaft from a proximal end towards a distal end of thedrive shaft. A portion of the pressurised fluid, after entering thetreated vessel distal to the abrasive element, flows in a retrogradedirection ‘RF’ around the abrasive element and across the treatedstenotic lesion to entrain abraded embolic particles ‘EP’ and evacuatethem from the treated vessel as soon as they have been abraded by theabrasive element of the device. Several embodiments of the device withdistal embolic protection capability are disclosed in WO 2006/126076,but in every one of these embodiments the retrograde flowing fluid RFand entrained embolic particles EP are evacuated through an oval lumenformed between a stationary drive shaft sheaf and the rotatable fluidimpermeable drive shaft. The retrograde flowing fluid RF and entrainedembolic particles EP are evacuated from the patient's body.

FIG. 6 is a side sectional view of the distal end portion of a sixthembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 6 is similar to the device of FIG. 4 except that thehollow drive shaft 42 has a fluid impermeable wall. The hollow driveshaft 42 is formed from a torque transmitting coil 43 and a fluidimpermeable membrane 47. FIG. 6 shows that the membrane 47 lines aninner surface of the torque transmitting coil 43. FIG. 6 illustratesthat this device is provided with distal protection capability, i.e.embolic particles abraded by the abrasive element 33′ are evacuated fromthe treated vessel 100. This device represents one of the embodiments ofthe rotational atherectomy device described in WO 2006/126076. FIG. 6shows that pressurised flushing fluid flows in an antegrade direction FFalong the lumen of the drive shaft 42 and enters the treated vessel 100through a luminal opening located distally to the abrasive element. Aportion of this fluid flows in a retrograde direction RF around theabrasive element 33′ and across the stenotic lesion 105 to entrainembolic particles EP abraded by the abrasive element. These embolicparticles are aspirated into an annular lumen formed between therotatable drive shaft 33′ and its stationary sheath 24′ and removed fromthe patient's body. FIG. 6 illustrates the device with a solid eccentricabrasive element 33′ and a pair of solid support elements 20D′, 20P′which have their centres of mass spaced away (offset) from therotational (longitudinal) axis of the drive shaft. During rotation ofthe drive shaft, these solid support elements act as counterweights tothe eccentric abrasive element The device of FIG. 6 may be advancedacross the stenotic lesion over a conventional guidewire, but theguidewire has to be removed from the device prior to attaching adetachable fluid supply tube to the device.

FIG. 7 is a side sectional view of the distal end portion of a seventhembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 7 is similar to the device of FIG. 6 except that thesolid abrasive element 35′ and the solid support elements 22D′, 22P′ aresymmetric with respect to a rotational (longitudinal) axis of the driveshaft 42′ (i.e. they have their centres of mass lying on a rotational(longitudinal) axis of the drive shaft 42′. The hollow drive shaft ofFIG. 7 is similar to the hollow drive shaft of FIG. 6 except that afluid impermeable membrane 47′ in FIG. 7 is shown extending around atorque transmitting coil 43′ of the drive shaft 43′. FIG. 7 illustratesoperation of the device in a curved vessel 100. The device of FIG. 7 hasbeen described in WO 2006/126076 and, as any other device described inWO 2006/126076, it may be (advanced across the stenotic lesionaround(over))(used with) a conventional guidewire. The guidewire has tobe removed from the device prior to attaching a detachable fluid supplytube to the device.

FIG. 8 is a side sectional view of the distal end portion of an eighthembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 8 is similar to the device of FIG. 6 except that thesupport elements 222D, 222P are fluid inflatable. These support elements222D, 222P are in fluid communication with the lumen of the drive shaft242 and are inflated by pressurised fluid flowing along the lumen of thedrive shaft in an antegrade direction FF.

Pressurised fluid inflates the support elements 222D, 222P and entersthe vessel through outflow openings 225 in the distal support element.FIG. 8 shows that the support elements, when inflated, are asymmetricwith respect to a rotational (longitudinal) axis of the drive shaft(i.e. the inflated support elements have there's centres of mass spacedaway (offset) from the rotational (longitudinal) axis of the driveshaftf). During rotation of the drive shaft, these inflated supportelements 222D, 222P act as counterweights to the eccentric abrasiveelement 235. The device of FIG. 8 has been described in WO 2006/126076and, as any other device described in WO 2006/126076, it may be(advanced across the stenotic lesion over a conventional guidewire. Theguidewire has to be removed from the device prior to connecting(attaching) a detachable fluid supply tube to the device.

FIG. 9 is a side sectional view of the distal end portion of a ninthembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 9 is similar to the device of FIG. 8 except that theabrasive element 235′ and the fluid inflatable support elements 222D′,222P′ shown in FIG. 9 are symmetric with respect to a rotational(longitudinal) axis of the drive shaft (i.e. they all have their centresof mass lying on a rotational (longitudinal) axis of the drive shaft.FIG. 9 shows operation of the device in a curved vessel 100. A stenoticlesion 105 is shown located on an inner curvature of the vessel 100.FIG. 9 illustrates a bias provided to the symmetric abrasive element235′ by a magnetic force or forces. The magnetic force or forces areindicated by arrows marked “MF”. The device of FIG. 9 has been describedin WO 2006/126076 and, as any other device described in WO 2006/126076,it may be advanced across the stenotic lesion over a conventionalguidewire. The guidewire has to be removed from the device prior toconnecting a detachable fluid supply tube to the device.

FIG. 9 shows an embodiment in which the centres of mass of the fluidinflatable support elements and the abrasive element are all lying onthe longitudinal axis of the drive shaft. However, it is also envisagedto provide an embodiment in which the centre of mass of the abrasiveelement is spaced radially away from the longitudinal axis of the driveshaft while the centers of mass of both of the distal and proximal fluidinflatable support elements are lying on the longitudinal axis of thedrive shaft. Such embodiment may be particularly applicable for use incarotid or femoral arteries.

FIG. 10 is a side sectional view of the distal end portion of a tenthembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 10 has been described in to Shturman (the instantinventor). The device of FIG. 10 is similar to the device of FIG. 6except that the solid counterweights 200D, 200P comprise outflowchannels 202D, 202P which extend radially outward with respect to arotational (longitudinal) axis of the drive shaft 252. FIG. 10illustrates that pressurised fluid flowing through these outflowchannels 202D, 202P forms fluid bearings between the solidcounterweights 200D, 200P and the wall of the treated vessel 100. Thisrotational atherectomy device may be advanced across the stenotic lesionover a conventional guidewire, but the guidewire has to be removed fromthe device prior to connecting a detachable fluid supply tube to thedevice.

FIG. 11 is a side sectional view of the distal end portion of aneleventh embodiment of the rotational atherectomy device of the priorart. The device of FIG. 10 has been described in to Shturman (theinstant inventor). The device of FIG. 11 is similar to the device ofFIG. 10 except that the outflow channels 202SD, 202SP are formed not inthe solid counterweights but in the solid support elements 200SD, 200SPwhich are symmetric with respect to a rotational (longitudinal) axis ofthe drive shaft. FIG. 11 illustrates operation of the device in a curvedvessel.

FIG. 11 shows an embodiment in which the centers of mass of the solidsupport elements 200SD, 200SP and the abrasive element 333 are lying onthe longitudinal axis of the drive shaft 252′. However, it is alsoenvisaged to provide an embodiment in which the centre of mass of theabrasive element is spaced radially away from the longitudinal axis ofthe drive shaft while the centers of mass of both of the distal andproximal solid support elements are lying on the longitudinal axis ofthe drive shaft. Such embodiment may be particularly applicable for usein carotid or femoral arteries.

FIG. 12 is a side sectional view of the distal end portion of a twelfthembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 12 is similar to the device of FIG. 8 except that thefluid inflatable counterweights 232D, 232P comprise outflow openings 226located such that pressurised fluid flowing through these openings 226forms fluid bearings between the fluid inflatable counterweights and thewall of the treated vessel 100.

FIG. 13 is a side sectional view of the distal end portion of athirteenth embodiment of the rotational atherectomy device of the priorart. The device of FIG. 13 has been described in to Shturman (theinstant inventor). The device of FIG. 13 is similar to the device ofFIG. 12 except that outflow openings are formed not in the fluidinflatable counterweights but in the fluid inflatable support elements232SD, 232SP which, when inflated, are symmetric with respect to arotational (longitudinal) axis of the drive shaft. The outflow openings226′ are located around entire circumferences of the symmetric fluidinflatable support elements such that pressurised fluid flowing throughthese openings forms fluid bearings between the walls of the fluidinflatable support elements and the wall of the treated vessel 100. FIG.13 shows an embodiment in which the centers of mass of the fluidinflatable support elements and the abrasive element are lying on thelongitudinal axis of the drive shaft. However, it is also envisaged toprovide an embodiment in which the centre of mass of the abrasiveelement is spaced radially away from the longitudinal axis of the driveshaft while the centres of mass of both of the distal and proximal fluidinflatable support elements are lying on the longitudinal axis of thedrive shaft. Such embodiment may be particularly applicable for use incarotid or femoral arteries.

FIGS. 13 to 15 b (FIG. 13 to FIG. 15b ) are side sectional views of thedistal end portions of two modifications of a fourteenth embodiment ofthe rotational atherectomy device of the prior art. FIGS. 13 to 15 billustrate that the torque transmitting coil 400 does not extend to thedistal end of the drive shaft 282, and the torque is transmitted to theabrasive element 450 by the fluid impermeable membrane 292 alone. FIGS.14A and 14B show fluid inflatable support elements 432SD, 432SP which,when inflated, are symmetric with respect to a rotational (longitudinal)axis of the drive shaft 282. FIGS. 15A and 15B show fluid inflatablecounterweights 432D, 432P which, when inflated, have their centres ofmass offset from the rotational longitudinal axis of the drive shaft282. FIGS. 15A and 15B illustrate a flexible leaf valve 400 which isformed at the distal end of the drive shaft 282 integrally with a wallof the distal fluid inflatable counterweight 432D. Preferably, theflexible valve 400 is moved to its closed position by pressure of fluid,which is pumped in an antegrade direction FF along the lumen of thedrive shaft 282 after advancing the drive shaft over a guidewire 4across a stenotic lesion to be treated and withdrawing the guidewirefrom the device. FIGS. 14A and 14B illustrate a flexible leaf valve 440formed at the distal end of the drive shaft 282 integrally with a wallof the distal fluid inflatable support element 432SD. The distal fluidinflatable support element 432SD, when inflated, is symmetric withrespect to a rotational (longitudinal) axis of the drive shaft 282.

It should be noted that FIGS. 14A and 14B show an eccentric abrasiveelement 450 mounted to the drive shaft between symmetric supportelements 432SD, 432SP, while FIGS. 15A and 15B show counterweights 432D,432P located on both sides of the eccentric abrasive element 460.

FIGS. 16 to 16 c (FIG. 16 to FIG. 16c ) are side sectional views of thedistal end portion of a fifteenth embodiment of the rotationalatherectomy device of the prior art. FIGS. 16 to 16 c illustrate thatthe outer torque transmitting coil 470 does not extend to the distal endof the drive shaft, and the torque is transmitted to the abrasiveelement by the inner torque transmitting coil 480 alone. FIGS. 16 to 16c illustrate formation of a ball valve at the distal end of the driveshaft 282 by a ball 495 and a shoulder 497 at the distal end of thedrive shaft.

All Shturman atherectomy devices known from WO 2006/126076 comprisedrainage lumen which is integral to the device. Most frequently thedrainage lumen has annular shape and (extends) (is formed)between therotatable drive shaft of the device and its stationary drive shaftsheaf. It should be noted that such annular drainage lumen has limitedwidth and will not permit removal out of the patient's body of embolicparticles measuring more than 200 microns in more than one dimension.The drainage lumen need not necessarily have an annular shape but therelatively limited cross sectional dimensions of any drainage lumenformed integrally with an atherectomy device create limitations foraspirating into such drainage lumen and removal out of the patient'sbody of embolic particles which measure more than 200 microns in morethan one dimension.

The present invention seeks to provide a rotational atherectomy systemwith distal embolic protection which includes a separate drainagecatheter and which will allow particles as large as about 1.5 mm indiameter to be aspirated from a treated vessel and the patient's bodythrough such separate drainage catheter.

Embodiments of the invention will now be described, by way of exampleonly, with reference to FIGS. 17 to 43 of the accompanying drawings, inwhich:

FIG. 1 is a side sectional view of a distal end portion of a firstembodiment of the rotational atherectomy device of the prior art. FIG. 1shows an abrasive burr which is attached to a distal end of a hollowflexible drive shaft. The abrasive surface is formed from diamondparticles electroplated to a front portion of the solid burr. The deviceis rotated around a special monofilament guidewire, and it iscommercially available.

FIG. 2 is a side sectional view of a distal end portion of a secondembodiment of the rotational atherectomy device of the prior art. Theabrasive element of FIG. 2 has an abrasive element which is locatedproximal to and spaced away from a distal end of the drive shaft. Thisabrasive element is formed from diamond particles electroplated directlyto wire turns of an enlarged diameter portion of the drive shaft. Theenlarged diameter portion of the drive shaft is asymmetric and isresponsible for providing the abrasive element with a centre of masswhich is spaced away from the rotational axis of the drive shaft. Thedevice is rotated around a special monofilament guidewire.

FIG. 3 is a side sectional view of a distal end portion of a thirdembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 3 is similar to the device of FIG. 2 except that theabrasive element comprises a prefabricated abrasive crown disposedaround the eccentric enlarged diameter portion of the drive shaft. Theprefabricated abrasive crown is formed from diamond particles bonded toa metallic sleeve rather than directly to wire turns of the drive shaft.The device is rotated around a special monofilament guidewire, and it iscommercially available.

FIG. 4 is a side sectional view of a distal end portion of a fourthembodiment of the rotational atherectomy device of the prior art. Therotational atherectomy device of FIG. 4 comprises a solid eccentricabrasive element and two solid support elements mounted on a hollowflexible drive shaft. The solid support elements are asymmetric withrespect to a rotational (longitudinal) axis of the drive shaft and,during rotation of the drive shaft, act as counterweights to theeccentric abrasive element. FIG. 4 illustrates operation of therotational atherectomy device with the eccentric abrasive element andtwo counterweights. The device is rotated around a special monofilamentguidewire which has to be withdrawn into the drive shaft prior tostarting its rotation.

FIG. 5 is a side sectional view of a distal end portion of a fifthembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 5 is similar to the device of FIG. 4 except that thesolid abrasive element and the solid support elements are symmetric withrespect to a rotational (longitudinal) axis of the drive shaft. FIG. 5illustrates operation of the device in a curved vessel. The device isrotated around a special mono filament guidewire which has to bewithdrawn into the drive shaft prior to starting its rotation.

FIG. 6 is a side sectional view of a distal end portion of a sixthembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 6 is similar to the device of FIG. 4 except that thehollow rotatable drive shaft has a fluid impermeable wall. FIG. 6illustrates that this device is provided with distal protectioncapability, i.e. embolic particles abraded by the abrasive element areevacuated from the treated vessel. FIG. 6 shows that pressurised fluidflows along the lumen of the drive shaft and enters the treated vesselthrough a luminal opening located distally to the abrasive element. Aportion of this fluid flows in a retrograde direction around theabrasive element and across the treated stenotic lesion to entrainembolic particles abraded by the abrasive element. These embolicparticles are aspirated into an annular lumen formed between therotatable drive shaft and its stationary sheaf. The aspirated embolicparticles are removed from the patient's body. The device of FIG. 6 maybe advanced across the stenotic lesion over a conventional guidewire,but the guidewire has to be removed from the device prior to attaching adetachable fluid supply tube to the device.

FIG. 7 is a side sectional view of a distal end portion of a seventhembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 7 is similar to the device of FIG. 6 except that thesolid abrasive element and the solid support elements are symmetric withrespect to a rotational (longitudinal) axis of the drive shaft.

FIG. 8 is a side sectional view of a distal end portion of an eighthembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 8 is similar to the device of FIG. 6 except that thesupport elements are fluid inflatable. These support elements are influid communication with the lumen of the drive shaft and are inflatedby pressurised fluid flowing along the lumen of the drive shaft. Thepressurised fluid inflates the support elements and enters the vesselthrough outflow openings therein. FIG. 8 shows that the supportelements, when inflated, are asymmetric with respect to a rotational(longitudinal) axis of the drive shaft and, during rotation of the driveshaft, act as counterweights to the eccentric abrasive element. Thedevice of FIG. 8 may be advanced across the stenotic lesion over aconventional guidewire, but the guidewire has to be removed from thedevice prior to attaching a detachable fluid supply tube to the device.

FIG. 9 is a side sectional view of a distal end portion of a ninthembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 9 is similar to the device of FIG. 8 except that theabrasive element and the fluid inflatable support elements are symmetricwith respect to a rotational (longitudinal) axis of the drive shaft.FIG. 9 illustrates operation of the device in a curved vessel.

FIG. 10 is a side sectional view of a distal end portion of a tenthembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 10 is similar to the device of FIG. 6 except that thesolid counterweights comprise channels which extend radially outwardwith respect to a rotational (longitudinal) axis of the drive shaft.FIG. 10 illustrates that pressurised fluid flowing through thesechannels forms fluid bearings between the counterweights and a wall ofthe treated vessel.

FIG. 11 is a side sectional view of a distal end portion of an eleventhembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 11 is similar to the device of FIG. 10 except that theabrasive element and the solid support elements are symmetric withrespect to a rotational (longitudinal) axis of the drive shaft. FIG. 11illustrates operation of the device in a curved vessel.

FIG. 12 is a side sectional view of a distal end portion of a twelfthembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 12 is similar to the device of FIG. 8 except that thefluid inflatable counterweights comprise outflow openings located suchthat pressurised fluid flowing through these openings forms fluidbearings between the fluid inflatable counterweights and a wall of thetreated vessel.

FIG. 13 is a side sectional view of a distal end portion of a thirteenthembodiment of the rotational atherectomy device of the prior art. Thedevice of FIG. 13 is similar to the device of FIG. 12 except that theabrasive element and the fluid inflatable support elements are symmetricwith respect to a rotational (longitudinal) axis of the drive shaft.

FIGS. 14A to 15B are side sectional views of distal end portions of twomodifications of a fourteenth embodiment of the rotational atherectomydevice of the prior art. These figures illustrate formation of two typesof a leaf valve at the distal end of the drive shaft.

FIGS. 16A to 16C are side sectional views of distal end portions of afifteenth embodiment of the rotational atherectomy device of the priorart. These figures illustrate formation of a ball valve at the distalend of the drive shaft.

FIG. 17 illustrates a first embodiment of a rotational atherectomysystem with enhanced distal embolic protection capability of the presentinvention, the rotational atherectomy system comprising a rotationalatherectomy device with counterweights and a separate drainage catheter,the retrograde flowing fluid being aspirated into the separate drainagecatheter, both the rotational atherectomy device and the drainagecatheter being shown inserted through separate openings located in thefemoral arteries of the patient and meeting in the aorta, the drainagecatheter extending into the common carotid artery while the rotationalatherectomy device passes through the common carotid artery and extendsfurther into the treated internal carotid artery. FIG. 17 illustratesthat the openings in the walls of the fluid inflatable counterweights ofthe device are located such that pressurized fluid flowing through theopenings forms fluid bearings between the walls of the fluid inflatedcounterweights and a wall of the treated vessel. FIG. 17 shows that anocclusion balloon is mounted to a catheter shaft of the drainagecatheter. The occlusion balloon has been inflated in the common carotidartery for temporarily engaging the atherectomy device and the drainagecatheter with each other and for restricting flow of fluids towards andaway from the treated stenotic lesion. FIG. 17 shows that the retrogradeflowing fluid and embolic particles are aspirated into the drainagelumen of the drainage catheter.

FIG. 17A is a cross-sectional view of the drainage catheter taken alongthe line A-A shown in FIG. 17;

FIG. 18 is an enlarged view of the rotational atherectomy system shownin FIG. 17.

FIGS. 18A to 18D illustrate distal ends of four exemplary atherectomydevices of the prior art. Any one of these four rotational atherectomydevices having distal counterweights shown in FIGS. 18A, 18B, 18C and18D (which correspond to the devices shown in FIGS. 10, 12, 15B and 16Crespectively) may be used as a rotational atherectomy device of thisfirst embodiment of the rotational atherectomy system with enhanceddistal embolic protection.

FIGS. 19A and 19B illustrate a preferred embodiment of the rotationalatherectomy device with counterweights which may be used as a rotationalatherectomy device of the rotational atherectomy system of theinvention. The rotational atherectomy device shown in FIGS. 19A and 19Bdiffers from the prior art devices shown in FIGS. 1 to 16C in that itdoes not require a guidewire for advancement towards and across astenotic lesion to be treated. FIGS. 19A and 19B show that the distalfluid inflatable counterweight is formed from a single fluid impermeablemembrane which extends around an anchoring sleeve of the device. Thisfluid impermeable membrane crosses a longitudinal axis of a long lumenof the device at the distal end of the device and prevents pressurizedfluid flowing along the long lumen from entering the treated vessel inthe direction of said longitudinal axis. FIG. 19B shows that thepressurized fluid has to pass through and inflate the distal fluidinflatable counterweight, prior to exiting from the device throughoutflow openings in the distal fluid inflatable counterweight in adirection different from the direction of the longitudinal axis of thelong lumen of the device. FIGS. 19A and 19B show that the long lumen ofthe device, the lumen of the drive shaft of the device and a torquetransmitting coil of the drive shaft have one common longitudinal axis.

FIG. 20 illustrates a modification of the preferred embodiment of therotational atherectomy device shown in FIGS. 19A and 19B. The device ofFIG. 20 is similar to the device of FIG. 19B except that the lumen ofthe drive shaft has proximal and distal portions and the proximalportion of the lumen has a larger cross-sectional area relative to thecross-sectional area of the distal portion of the lumen. Thereby, perunit of length, the hydraulic resistance to fluid flow of the proximalportion of the lumen is less than the hydraulic resistance to fluid flowof the distal portion of the lumen.

FIGS. 21A and 21B illustrate another modification of the preferredembodiment of the rotational atherectomy device with counterweightsshown in FIGS. 19A and 19B. FIGS. 21A and 21B illustrate the rotationaldevice with fluid inflatable counterweights which has been advancedacross the stenotic lesion to a position in which the distal fluidinflatable counterweight has been located distal to the stenotic lesionand the proximal fluid inflatable counterweight has been intentionallylocated proximal to the stenotic lesion to be treated. The device ofFIGS. 21A and 2113 is similar to the device of FIGS. 19A and 19B, butdiffers in that it comprises an elongate core element disposed in thelumen of the drive shaft to stiffen the drive shaft and thereby assistin the advancement of the device along the vessel towards and across thestenotic lesion. The elongate core element comprises a long lumen, saidlumen being in fluid communication with the lumen of the drive shaftthrough an opening located in a wall of the core element adjacent to itsdistal end. The continuous flow of the pressurized fluid from the lumenof the core element into the lumen of the drive shaft assists inremoving the core element from the lumen of the drive shaft withoutchanging position of the device in the treated vessel. Furthermore, thedistal support element, when inflated, may be anchored distal to thestenotic lesion. Such inflating and anchoring of the distal supportelement against the stenotic lesion may help in removing the coreelement from the lumen of the drive shaft without changing position ofthe device in the treated vessel.

FIG. 22 illustrates a modification of the first embodiment of therotational atherectomy system with enhanced distal embolic protectioncapability. The system of FIG. 22 is similar to the system of FIG. 18except that the system of FIG. 22 comprises one of the rotationalatherectomy devices shown in FIGS. 19A to 21B, i.e. the rotationalatherectomy device in which a fluid impermeable wall of the distal fluidinflatable counterweight prevents pressurized fluid flowing along thelumen of the drive shaft from entering the treated vessel in thedirection of the longitudinal axis of the drive shaft. FIG. 22 showsthat pressurized fluid is exiting from the device only through outflowopenings in the distal fluid inflatable counterweight. FIG. 22 showsthat the openings in the walls of the fluid inflatable counterweightsare located such that pressurized fluid flowing through the openingsforms fluid bearings between the walls of the fluid inflatedcounterweights and a wall of the treated vessel.

FIG. 22A illustrates a distal end of an exemplary atherectomy devicewith fluid inflatable counterweights which may be used as a rotationalatherectomy device of the rotational atherectomy system of the inventionshown in FIG. 22. Any one of the three rotational atherectomy devicesshown in FIGS. 19A to 21B may be used as the rotational atherectomydevice of this first embodiment of the rotational atherectomy systemwith enhanced distal embolic protection.

FIG. 23 illustrates a second embodiment of the rotational atherectomysystem with enhanced distal protection capability. The system of FIG. 23is similar to the system of FIG. 17 except that the rotationalatherectomy device of FIG. 23, instead of counterweights, has supportelements having centres of mass lying along the rotational(longitudinal) axis of the drive shaft of the device;

FIG. 23A is a cross-sectional view of the drainage catheter taken alongthe line A-A shown in FIG. 23;

FIG. 24 is an enlarged view of the rotational atherectomy system shownin FIG. 23. FIG. 24 illustrates that the openings in the walls of thefluid inflatable support elements of the rotational atherectomy deviceare located such that pressurized fluid flowing through the openingsforms fluid bearings between the walls of the fluid inflated supportelements and a wall of the treated vessel. FIG. 24 shows that anocclusion balloon is mounted to a catheter shaft of the drainagecatheter. The occlusion balloon has been inflated in the common carotidartery for temporarily engaging the atherectomy device and the drainagecatheter with each other and for restricting flow of fluids towards andaway from the treated stenotic lesion.

FIGS. 24A to 24C illustrate distal ends of exemplary atherectomy devicesof the prior art which may be used as a rotational atherectomy device ofthe rotational atherectomy system of the invention shown in FIG. 24. Anyone of the three rotational atherectomy devices having distal supportelements shown in FIGS. 24A, 24B and 24C (which correspond to thedevices shown in FIGS. 11, 13, and 14B respectively) may be used as arotational atherectomy device of this second embodiment of therotational atherectomy system with enhanced distal embolic protection.

FIGS. 25A and 25B illustrate a preferred embodiment of the rotationalatherectomy device with fluid inflatable support elements which may beused as a rotational atherectomy device of the second embodiment of therotational atherectomy system of the invention. The rotationalatherectomy device shown in FIGS. 25A and 25B is similar to therotational atherectomy device shown in FIGS. 19A and 19B, but differs inthat the centres of mass of the inflatable support elements are layingon the longitudinal axis of the torque transmitting coil and of thelumen of the drive shaft. FIG. 25B shows the device of FIG. 25A after anantegrade flow of fluid has been initiated and the support elements havebeen inflated. FIG. 25B illustrates that fluid inflatable spaces withinthe support elements extend uniformly around the longitudinal axis ofthe torque transmitting coil and the lumen of the drive shaft, thereforeproviding the fluid inflated support elements with centres of mass whichare laying on the longitudinal axis of the torque transmitting coil andthe lumen of the drive shaft.

FIGS. 26A and 26B illustrate a modification of the preferred embodimentof the rotational atherectomy device shown in FIGS. 25A and 25B. Thedevice shown in FIGS. 26A and 26B is similar to the rotationalatherectomy device shown in FIGS. 19A and 19B, but differs in that thedrive shaft comprises inner and outer torque transmitting coils.

FIG. 27 illustrates a modification of the second embodiment of therotational atherectomy system with enhanced distal embolic protectioncapability. The system of FIG. 27 is similar to the system of FIG. 24except that the system of FIG. 27 comprises one of the rotationalatherectomy devices shown in FIGS. 25A to 26B, i.e. the rotationalatherectomy device in which a fluid impermeable wall of the distal fluidinflatable support element prevents pressurized fluid flowing along thelumen of the drive shaft from entering the treated vessel in thedirection of the longitudinal axis of the drive shaft. FIG. 27 showsthat pressurized fluid is exiting from the device only through outflowopenings in the fluid inflatable support elements. FIG. 27 shows thatthe openings in the walls of the fluid inflatable support elements arelocated such that pressurized fluid flowing through the openings formsfluid bearings between the walls of the fluid inflated support elementsand a wall of the treated vessel. FIG. 27 shows that an occlusionballoon is mounted to a catheter shaft of the drainage catheter. Theocclusion balloon has been inflated in the common carotid artery fortemporarily engaging the atherectomy device and the drainage catheterwith each other and for restricting flow of fluids towards and away fromthe treated stenotic lesion. FIG. 27 shows that the retrograde flowingfluid and embolic particles are aspirated into the drainage lumen of thedrainage catheter.

FIGS. 27A and 27B illustrate distal ends of exemplary atherectomydevices with fluid inflatable support elements shown in FIGS. 25A to26B. Any one of the two rotational atherectomy devices shown in FIGS.25A to 26B may be used as a rotational atherectomy device of thismodification of the second embodiment of the rotational atherectomysystem shown in FIG. 27.

FIG. 28 illustrates how the second embodiment of the rotationalatherectomy system of the invention may be used for treatment of thestenotic lesion located in the superficial femoral artery. FIG. 28 showsthat the rotational atherectomy device and the drainage catheter havebeen introduced into the patient's vasculature through separate openingslocated in the radial arteries of the patient. The atherectomy deviceand the drainage catheter are meeting in the aorta and extending intothe treated femoral artery of a patient. FIG. 28 shows that an occlusionballoon is mounted to a catheter shaft of the drainage catheter. Theocclusion balloon has been inflated in the femoral artery proximal tothe treated stenotic lesion for temporarily engaging the atherectomydevice and the drainage catheter with each other and for restrictingflow of fluids towards and away from the treated stenotic lesion. Theretrograde flowing fluid and embolic particles are aspirated into thedrainage lumen of the drainage catheter.

FIG. 29 is an enlarged view of the rotational atherectomy system shownin FIG. 28;

FIG. 30 is similar to FIG. 29 except that it shows the modifiedrotational atherectomy system of the second embodiment. The system ofFIG. 30 is similar to the system of FIG. 29 except that the system ofFIG. 30 comprises one of the rotational atherectomy devices shown inFIGS. 25A to 26B, i.e. the rotational atherectomy device in which afluid impermeable wall of the distal fluid inflatable support elementprevents pressurized fluid flowing along the lumen of the drive shaftfrom entering the treated vessel in the direction of the longitudinalaxis of the drive shaft.

FIGS. 30A and 30B illustrate distal ends of exemplary atherectomydevices with fluid inflatable support elements shown in FIGS. 25A to26B. Any one of the two rotational atherectomy devices shown in FIGS.25A to 26B may be used as a rotational atherectomy device of thismodification of the second embodiment of the rotational atherectomysystem shown in FIG. 30.

FIG. 31 is similar to FIG. 29, but differs in that the occlusion balloonis mounted to a drive shaft sheath of the rotational atherectomy deviceinstead of being mounted to the catheter shaft of the drainage catheter.

FIG. 32 is similar to FIG. 28, but differs in that both the rotationalatherectomy device and the drainage catheter have been introduced intothe patient's vasculature through separate openings located in thebrachial arteries of the patient.

FIG. 33 illustrates a third embodiment of the rotational atherectomysystem with enhanced distal embolic protection capability. The system ofFIG. 33 is similar to the systems of the first and second embodiments inthat it includes both a separate rotational atherectomy device and aseparate drainage catheter. The rotational atherectomy system of thethird embodiment differs from the systems of the first and secondembodiments in that it includes a rotational atherectomy device withoutsupport elements or counterweights. FIG. 33 shows that the rotationalatherectomy system of the third embodiment includes an orbitalatherectomy device of the prior art shown in FIG. 3 but it should beunderstood that it may instead include a classic rotational atherectomydevice of the prior art shown in FIG. 1.

FIG. 34 illustrates a fourth embodiment of the rotational atherectomysystem with enhanced distal protection capability. The system of FIG. 34is similar to the system of FIG. 33 except that it includes an externalocclusion cuff. FIG. 34 shows that tibial arteries and the most distalsegment of the popliteal artery have been occluded by an inflatedexternal occlusion cuff so that any embolic particles abraded by theatherectomy device and not entrained in the retrograde flowing flushingfluid accumulate distal to the site of the treated stenotic area butproximal to a point at which the inflated occlusion cuff has compressedthe treated vessel or its distal branches.

FIG. 35 is similar to FIG. 34, but shows that the occlusion balloon ofthe drainage catheter has been deflated and the drainage catheter hassubsequently been advanced sufficiently close to the accumulated embolicparticles. FIG. 35 also shows that the rotational atherectomy device hasbeen withdrawn proximally away from the stenotic lesion to affordmovement of the drainage catheter closer to the accumulated embolicparticles;

FIG. 36 illustrates an inflated external occlusion cuff for occludingthe tibial and the most distal segment of the popliteal artery, the cuffcomprising a zip fastener for closing the inflatable cuff in positionaround the patient's calf. FIG. 30 shows that the zip fastener extendsover the patient's tibia (a front aspect of the patient's calf);

FIG. 37 illustrates a first modification of the external occlusion cuff.The external occlusion cuff of FIG. 37 is similar to the externalocclusion cuff of FIG. 36 except that the zip fastener in FIG. 37 isshown extending over the lateral aspect of the patient's calf;

FIG. 38 illustrates a second modification of the external occlusioncuff. The external occlusion cuff of FIG. 38 is similar to the externalocclusion cuff of FIG. 37 except that end portions of the zip fastenerin FIG. 38 are shown extending beyond the inflatable portion of the cuffin both distal and proximal directions;

FIG. 39 illustrates a third modification of the external occlusion cuff.The external occlusion cuff of FIG. 39 is similar to the externalocclusion cuff of FIG. 38 except that the zip fastener in FIG. 39 isshown extending over the lateral aspect of the patient's calf;

FIG. 40 illustrates a fourth modification of the external occlusioncuff. The external occlusion cuff of FIG. 40 is similar to the externalocclusion cuff of FIG. 38 except that the engageable teeth portion ofthe zip fastener in FIG. 40 does not extend to the distal and proximalends of the zip fastener, thereby enabling the circumference of the cuffto be enlarged without completely opening it;

FIG. 41 illustrates a fifth modification of the external occlusion cuff.The external occlusion cuff of FIG. 41 is similar to the externalocclusion cuff of FIG. 40 except that the zip fastener in FIG. 41 isshown extending over the lateral aspect of the patient's calf;

FIG. 42 illustrates a fifth modification of the external occlusion cuff.FIG. 42 shows an inflatable occlusion cuff having a shape of a sock andcomprising a zip fastener which extends over the lateral aspect of thepatient's calf;

FIG. 43 illustrates a sixth modification of the external occlusion cuff.The external occlusion cuff of FIG. 43 is similar to the externalocclusion cuff of FIG. 42 except that the zip fastener of FIG. 43 has azip fastener portion that extends proximally from the inflatable portionof the cuff;

Reference is made in this specification to “distal” and “proximal” endsof the device. For the purpose of this specification, the distal end isconsidered to refer to the end of the device which is advanced into thevessel in the body of a patient and, the proximal end is the oppositeend of the device which remains outside the body of the patient. Theproximal end of the device is connected to fluid pumping and suctiondevices. The term “antegrade flow” refers to a direction of fluid flowfrom the proximal to the distal end of the device. Similarly, and theterm “retrograde flow” refers to a direction of fluid flow in theopposite direction, i.e. from the distal to the proximal end of thedevice. The antegrade flowing fluid is indicated by arrows ‘FF’. Theretrograde flowing fluid is indicated by arrows ‘RF’. Embolic particlesare indicated by symbol ‘EP’. Reference ‘W-W’ indicates a rotational(longitudinal) axis of the drive shaft.

FIG. 17 illustrates a first embodiment of a rotational atherectomysystem with enhanced distal embolic protection capability of the presentinvention, the rotational atherectomy system comprising a rotationalatherectomy device with counterweights and a separate drainage catheter,the retrograde flowing fluid being aspirated into the separate drainagecatheter, both the rotational atherectomy device 777 and the drainagecatheter 800 being shown inserted through separate openings located inthe femoral arteries 900 of the patient and meeting in the aorta 966,the drainage catheter 800 extending into the common carotid artery 999while the rotational atherectomy device 777 passes through the commoncarotid artery and extends further into the treated internal carotidartery 1500. FIG. 17 illustrates that the openings in the wall of thedistal fluid inflatable counterweight of the device are located suchthat pressurized fluid flowing through the openings forms a fluidbearing between the wall of the fluid inflated distal counterweight anda wall of the treated vessel. FIG. 17 shows that an occlusion balloon1116 is mounted to a catheter shaft 1115 of the drainage catheter 800.The occlusion balloon 1116 has been inflated in the common carotidartery 999 for temporarily engaging the atherectomy device 777 and thedrainage catheter 800 with each other and for restricting flow of fluidstowards and away from the treated stenotic lesion 666. FIG. 17 showsthat the retrograde flowing fluid and embolic particles are aspiratedinto the drainage lumen of the drainage catheter 800.

It should be noted that it is preferable to provide the occlusionballoon on the drainage catheter rather than on the stationary sheath ofthe rotational atherectomy device because it results in a simpler designand operation of the atherectomy device.

FIG. 17A is a cross-sectional view of the drainage catheter 800 takenalong the line A-A shown in FIG. 17. It shows drainage lumen 1120 andseparate occlusion balloon inflation lumen 1119.

FIG. 18 is an enlarged view of the rotational atherectomy system shownin FIG. 17.

FIGS. 18A to 18D illustrate distal ends of four exemplary atherectomydevices of the prior art. Any one of these four rotational atherectomydevices having distal counterweights 200D, 232D, 432D and 432D′, shownin FIGS. 18A, 18B, 18C and 18D and corresponding to the devices shown inFIGS. 10, 12, 15B and 16C respectively, may be used as a rotationalatherectomy device 777 of this first embodiment of the rotationalatherectomy system with enhanced distal embolic protection.

FIGS. 19A and 19B illustrate a preferred embodiment of the rotationalatherectomy device with counterweights which may be used as a rotationalatherectomy device of the rotational atherectomy system of theinvention.

The rotational atherectomy device shown in FIGS. 19A and 19B differsfrom the prior art devices shown in FIGS. 1 to 16C in that it does notrequire a guidewire for advancement towards and across a stenotic lesionto be treated. FIGS. 19A and 19B show that the distal fluid inflatablecounterweight 1300 is formed from a single fluid impermeable membrane1900 which extends around an anchoring sleeve 1715 of the device. Thisfluid impermeable membrane crosses a longitudinal axis W-W of a longlumen 1600 of the device at the distal end of the device and preventspressurized fluid flowing along the long lumen in an antegrade direction‘FF’ from entering the treated vessel in the direction of saidlongitudinal axis W-W. FIG. 19B shows that the pressurized fluid has topass through and inflate the distal fluid inflatable counterweight 1300,prior to exiting from the device through outflow openings 1666 in thedistal fluid inflatable counterweight 1300 in a direction different fromthe direction of the longitudinal axis W-W of the long lumen 1600 of thedevice. FIGS. 19A and 19B show that the long lumen 1600 of the device,the lumen of the drive shaft 1601 of the device and a torquetransmitting coil 1602 of the drive shaft 1601 have one commonlongitudinal axis W-W.

FIG. 20 illustrates a modification of the preferred embodiment of therotational atherectomy device shown in FIGS. 19A and 19B. The device ofFIG. 20 is similar to the device of FIG. 19B except that the lumen 1600of the drive shaft 1601′ has proximal and distal portions and theproximal portion 1800 of the lumen has a larger cross-sectional arearelative to the cross-sectional area of the distal portion 1900 of thelumen. Thereby, per unit of length, the hydraulic resistance to fluidflow of the proximal portion of the lumen is less than the hydraulicresistance to fluid flow of the distal portion of the lumen.

FIGS. 21A and 21B illustrate another modification of the preferredembodiment of the rotational atherectomy device with counterweightsshown in FIGS. 19A and 19B. FIGS. 21A and 21B illustrate the rotationaldevice with fluid inflatable counterweights which has been advancedacross the stenotic lesion 2000 to a position in which the distal fluidinflatable counterweight 1300 has been located distal to the stenoticlesion 2000 and the proximal fluid inflatable counterweight 2300 hasbeen intentionally located proximal to the stenotic lesion to betreated. The device of FIGS. 21A and 21B is similar to the device ofFIGS. 19A and 19B, but differs in that it comprises an elongate coreelement 3000 disposed in the lumen of the drive shaft to stiffen thedrive shaft and thereby assist in the advancement of the device alongthe vessel towards and across the stenotic lesion. The elongate coreelement comprises a long lumen, said lumen being in fluid communicationwith the lumen of the drive shaft through an opening located in a wallof the core element adjacent to its distal end. The continuous flow ofthe pressurized fluid from the lumen of the core element into the lumenof the drive shaft assists in removing the core element 3000 from thelumen 1600 of the drive shaft without changing position of the device inthe treated vessel. Furthermore, the distal counterweight 1300, wheninflated, may be anchored distal to the stenotic lesion 2000. Suchinflating and anchoring of the distal counterweight against the stenoticlesion may help in removing the core element from the lumen of the driveshaft without changing position of the device in the treated vessel.

FIG. 22 illustrates a modification of the first embodiment of therotational atherectomy system with enhanced distal embolic protectioncapability. The system of FIG. 22 is similar to the system of FIG. 18except that the system of FIG. 22 comprises one of the rotationalatherectomy devices shown in FIGS. 19A to 21B, i.e. the rotationalatherectomy device in which a fluid impermeable wall of the distal fluidinflatable counterweight prevents pressurized fluid flowing along thelumen of the drive shaft from entering the treated vessel in thedirection of the longitudinal axis of the drive shaft. FIG. 22 showsthat pressurized fluid is exiting from the device 777′ only throughoutflow openings in the distal and proximal fluid inflatablecounterweights. FIG. 22 shows that the openings 1666 in the walls of thefluid inflatable counterweights are located such that pressurized fluidflowing through the openings form fluid bearings between the walls ofthe fluid inflated counterweights and a wall of the treated vessel.

FIG. 22A illustrates a distal end of an exemplary atherectomy devicewith fluid inflatable counterweights 1300 which may be used as arotational atherectomy device 777′ of the rotational atherectomy systemof the invention shown in FIG. 22. Any one of the three rotationalatherectomy devices shown in FIGS. 19A to 21B may be used as therotational atherectomy device of this first embodiment of the rotationalatherectomy system with enhanced distal embolic protection.

FIG. 23 illustrates a second embodiment of the rotational atherectomysystem with enhanced distal protection capability. The system of FIG. 23is similar to the system of FIG. 17 except that the rotationalatherectomy device 778 of FIG. 23, instead of counterweights, hassupport elements having centres of mass lying along the rotational(longitudinal) axis of the drive shaft of the device;

FIG. 23A is a cross-sectional view of the drainage catheter 800 takenalong the line A-A shown in FIG. 23;

FIG. 24 is an enlarged view of the rotational atherectomy system shownin FIG. 23. FIG. 24 illustrates that the openings in the walls of thedistal fluid inflatable support elements of the rotational atherectomydevice are located such that pressurized fluid flowing through theopenings form fluid bearings between the walls of the fluid inflatedsupport elements and a wall of the treated vessel. FIG. 24 shows that anocclusion balloon 1116 is mounted to a catheter shaft 1115 of thedrainage catheter. The occlusion balloon 1116 has been inflated in thecommon carotid artery 999 for temporarily engaging the atherectomydevice 778 and the drainage catheter 800 with each other and forrestricting flow of fluids towards and away from the treated stenoticlesion.

FIGS. 24A to 24C illustrate distal ends of exemplary atherectomy devicesof the prior art which may be used as a rotational atherectomy device ofthe rotational atherectomy system of the invention shown in FIG. 24. Anyone of the three rotational atherectomy devices having distal supportelements 200SD, 232SD and 432SD shown in FIGS. 24A, 24B and 24Crespectively (which correspond to the devices shown in FIGS. 11, 13 and14B respectively), may be used as a rotational atherectomy device 778 ofthis second embodiment of the rotational atherectomy system withenhanced distal embolic protection.

FIGS. 25A and 25B illustrate a preferred embodiment of the rotationalatherectomy device with fluid inflatable support elements which may beused as a rotational atherectomy device of the second embodiment of therotational atherectomy system of the invention. The rotationalatherectomy device shown in FIGS. 25A and 25B is similar to therotational atherectomy device shown in FIGS. 19A and 19B, but differs inthat the centres of mass of the inflatable support elements 1300S, 2300Sare laying on the longitudinal axis W-W of the torque transmitting coil1602 and of the lumen 1600 of the drive shaft 1601′. FIG. 25B shows thedevice of FIG. 25A after an antegrade flow FF of fluid has beeninitiated and the support elements have been inflated. FIG. 25Billustrates that fluid inflatable spaces 444, 446 within the supportelements 1300S, 2300S extend uniformly around the longitudinal axis W-Wof the torque transmitting coil 1602 and the lumen of the drive shaft1601, therefore providing the fluid inflated support elements 1300S,2300S with centres of mass which are laying on the longitudinal axis W-Wof the torque transmitting coil 1602 and the lumen 1600 of the driveshaft 1601′.

FIGS. 26A and 26B illustrate a modification of the preferred embodimentof the rotational atherectomy device shown in FIGS. 25A and 25B. Thedevice shown in FIGS. 26A and 26B is similar to the rotationalatherectomy device shown in FIGS. 19A and 19B, but differs in that thedrive shaft 1601′ comprises inner and outer torque transmitting coils1611, 1612.

FIG. 27 illustrates a modification of the second embodiment of therotational atherectomy system with enhanced distal embolic protectioncapability. The system of FIG. 27 is similar to the system of FIG. 24except that the system of FIG. 27 comprises one of the rotationalatherectomy devices shown in FIGS. 25A to 26B, i.e. the rotationalatherectomy device in which a fluid impermeable wall 1900 of the distalfluid inflatable support element 1300S prevents pressurized fluidflowing along the lumen of the drive shaft from entering the treatedvessel in the direction of the longitudinal axis of the drive shaft1601′. FIG. 27 shows that pressurized fluid is exiting from the deviceonly through outflow openings in the distal and proximal fluidinflatable support elements 1300S, 2300. FIG. 27 shows that the openingsin the walls of the distal and proximal fluid inflatable supportelements are located such that pressurized fluid flowing through theopenings forms a fluid bearing between the walls of the fluid inflateddistal and proximal support elements and a wall of the treated vessel.FIG. 27 shows that an occlusion balloon 1116 is mounted to a cathetershaft 1115 of the drainage catheter 800. The occlusion balloon has beeninflated in the common carotid artery for temporarily engaging theatherectomy device and the drainage catheter with each other and forrestricting flow of fluids towards and away from the treated stenoticlesion. FIG. 27 shows that the retrograde flowing fluid and embolicparticles are aspirated into the drainage lumen of the drainage catheter800.

FIGS. 27A and 27B illustrate distal ends of exemplary atherectomydevices with fluid inflatable support elements shown in FIGS. 25A to 26Brespectively. Any one of the two rotational atherectomy devices shown inFIGS. 25A to 26B may be used as a rotational atherectomy device 778′ ofthis modification of the second embodiment of the rotational atherectomysystem shown in FIG. 27.

FIG. 28 illustrates how the second embodiment of the rotationalatherectomy system of the invention may be used for treatment of thestenotic lesion located in the superficial femoral artery 3300. FIG. 28shows that the rotational atherectomy device 778 and the drainagecatheter 800 have been introduced into the patient's vasculature throughseparate openings located in the radial arteries 3400 of the patient.The atherectomy device and the drainage catheter are meeting in theaorta 966 and extending into the treated femoral artery 3300 of apatient. FIG. 28 shows that an occlusion balloon 1116 is mounted to acatheter shaft 1115 of the drainage catheter 800. The occlusion balloonhas been inflated in the femoral artery proximal to the treated stenoticlesion for temporarily engaging the atherectomy device and the drainagecatheter with each other and for restricting flow of fluids towards andaway from the treated stenotic lesion 666. The retrograde flowing fluidand embolic particles are aspirated into the drainage lumen of thedrainage catheter 800.

FIG. 29 is an enlarged view of the rotational atherectomy system shownin FIG. 28;

FIG. 30 is similar to FIG. 29 except that it shows the modifiedrotational atherectomy system of the second embodiment. The system ofFIG. 30 is similar to the system of FIG. 29 except that the system ofFIG. 30 comprises one of the rotational atherectomy devices shown inFIGS. 25A to 26B, i.e. the rotational atherectomy device 778′ in which afluid impermeable wall of the distal fluid inflatable support elementprevents pressurized fluid flowing along the lumen of the drive shaftfrom entering the treated vessel in the direction of the longitudinalaxis of the drive shaft.

FIGS. 30A and 30B illustrate distal ends of exemplary atherectomydevices with fluid inflatable support elements shown in FIGS. 25A to26B. Any one of the two rotational atherectomy devices shown in FIGS.25A to 26B may be used as a rotational atherectomy device 778′ of thismodification of the second embodiment of the rotational atherectomysystem shown in FIG. 30.

FIG. 31 is similar to FIG. 30, but differs in that the occlusion balloonis mounted to a drive shaft sheath 1778 of the rotational atherectomydevice 778′ instead of being mounted to the catheter shaft of thedrainage catheter 800′.

FIG. 32 is similar to FIG. 28, but differs in that both the rotationalatherectomy device 778 and the drainage catheter 800 have beenintroduced into the patient's vasculature through separate openingslocated in the brachial arteries 7000 of the patient.

FIG. 33 illustrates a third embodiment of the rotational atherectomysystem with enhanced distal embolic protection capability. The system ofFIG. 33 is similar to the systems of the first and second embodiments inthat it includes both a separate rotational atherectomy device and aseparate drainage catheter. The rotational atherectomy system of thethird embodiment differs from the systems of the first and secondembodiments in that it includes a rotational atherectomy device withoutsupport elements or counterweights. FIG. 33 shows that the rotationalatherectomy system of the third embodiment includes an orbitalatherectomy device 5000 of the prior art shown in FIG. 3 but it shouldbe understood that it may instead include a classic rotationalatherectomy device of the prior art shown in FIG. 1.

FIG. 34 illustrates a fourth embodiment of the rotational atherectomysystem with enhanced distal protection capability. The system of FIG. 34is similar to the system of FIG. 33 except that it includes an externalocclusion cuff 4400. FIG. 34 shows that tibial arteries and the mostdistal segment of the popliteal artery have been occluded by an inflatedexternal occlusion cuff 4400. FIG. 34 illustrates any embolic particlesEP abraded by the atherectomy device and not immediately evacuatedthrough the drainage catheter 800 accumulate distal to the site of thetreated stenotic area but proximal to a point at which the inflatedocclusion cuff has compressed the treated vessel or its distal branches.

FIG. 35 shows that the occlusion balloon 1116 of the drainage catheter800 shown in FIG. 34, has been deflated and the drainage catheter 800has subsequently been advanced sufficiently close to the embolicparticles EP accumulated proximal to the segment of the artery occludedby the external occlusion cuff 4400. FIG. 35 also shows that therotational atherectomy device 5000 has been withdrawn proximally awayfrom the stenotic lesion 666 to afford movement of the drainage catheter800 closer to the accumulated embolic particles.

FIG. 36 illustrates an inflated external occlusion cuff 4400 foroccluding the tibial and the most distal segment of the poplitealartery, the cuff comprising a zip fastener 6000 for closing theinflatable cuff in position around the patient's calf. FIG. 30 showsthat the zip fastener extends over the patient's tibia (a front aspectof the patient's calf);

FIG. 37 illustrates a first modification of the external occlusion cuff.The external occlusion cuff of FIG. 37 is similar to the externalocclusion cuff of FIG. 36 except that the zip fastener in FIG. 37 isshown extending over the lateral aspect of the patient's calf;

FIG. 38 illustrates a second modification of the external occlusioncuff. The external occlusion cuff of FIG. 38 is similar to the externalocclusion cuff of FIG. 37 except that end portions of the zip fastenerin FIG. 38 are shown extending beyond the inflatable portion of the cuffin both distal and proximal directions;

FIG. 39 illustrates a third modification of the external occlusion cuff.The external occlusion cuff of FIG. 39 is similar to the externalocclusion cuff of FIG. 38 except that the zip fastener in FIG. 39 isshown extending over the lateral aspect of the patient's calf;

FIG. 40 illustrates a fourth modification of the external occlusioncuff. The external occlusion cuff of FIG. 40 is similar to the externalocclusion cuff of FIG. 38 except that the engageable teeth portion ofthe zip fastener in FIG. 40 does not extend to the distal and proximalends of the zip fastener, thereby enabling the circumference of the cuffto be enlarged without completely opening it;

FIG. 41 illustrates a fifth modification of the external occlusion cuff.The external occlusion cuff of FIG. 41 is similar to the externalocclusion cuff of FIG. 40 except that the zip fastener in FIG. 41 isshown extending over the lateral aspect of the patient's calf;

FIG. 42 illustrates a fifth modification of the external occlusion cuff.FIG. 42 shows an inflatable occlusion cuff having a shape of a sock andcomprising a zip fastener which extends over the lateral aspect of thepatient's calf;

FIG. 43 illustrates a sixth modification of the external occlusion cuff.The external occlusion cuff of FIG. 43 is similar to the externalocclusion cuff of FIG. 42 except that the zip fastener of FIG. 43 has azip fastener portion that extends proximally from the inflatable portionof the cuff;

1.-20. (canceled)
 21. A method for performing rotational atherectomy toremove stenotic lesion material from a blood vessel of a patient, themethod comprising: delivering a rotational atherectomy system into theblood vessel, wherein the rotational atherectomy system comprises: anelongate drainage catheter defining a first lumen and a second lumen,the drainage catheter including an inflatable balloon member attached toand surrounding an outer diameter of a distal end portion of thedrainage catheter, the balloon member in fluid communication with thefirst lumen, the balloon member configured to contact a blood vesselwall when the balloon member is in an inflated configuration; and arotational atherectomy device slidable through the elongate drive shaftsheath toward stenotic lesion material in the blood vessel, comprising:an elongate flexible drive shaft comprising an inner torque transmittingcoil and defining a central lumen and a longitudinal axis, the driveshaft configured for rotation about the longitudinal axis, the driveshaft configured to be at least partially disposed within the bloodvessel and at least partially disposed within the second lumen when thesystem is used for performing the rotational atherectomy; an abrasiveelement that is mounted to the drive shaft such that a center of mass ofthe abrasive element is offset from the longitudinal axis of the driveshaft; a proximal stability element that is fixed to the drive shaft andthat has a center of mass coaxial with the longitudinal axis of thedrive shaft, the proximal stability element being proximally spacedapart from the abrasive element by a first distance; a distal stabilityelement that is fixed to the drive shaft and that has a center of masscoaxial with the longitudinal axis of the drive shaft, the distalstability element being distally spaced apart from the abrasive elementby the first distance; and a fluid impermeable membrane along the driveshaft and surrounding an outer diameter of the drive shaft at least fromthe proximal stability element to the distal stability element; androtating the drive shaft about the longitudinal axis such that theabrasive element contacts the stenotic lesion material.
 22. The methodof claim 21, wherein during said rotation, the abrasive element has anorbital path about an axis of rotation, the orbital path having asubstantially greater diameter than a travel path of each of theproximal and distal stability elements.
 23. The method of claim 21,wherein the delivering the rotational atherectomy device into the bloodvessel comprises advancing the drive shaft over a guidewire across thestenotic lesion.
 24. The method of claim 21, wherein the rotating causesthe abrasive element to remove lesion material particles from thestenotic lesion.
 25. The method of claim 21, wherein the proximal anddistal stability elements are equally spaced apart from the abrasiveelement.
 26. The method of claim 21, wherein the proximal and distalstability elements comprise inflatable stability elements.
 27. Themethod of claim 21, wherein the rotational atherectomy system furthercomprises an elongate drive shaft sheath defining a sheath lumentherethrough, the drive shaft sheath being configured to be at leastpartially disposed within the blood vessel, the drive shaft beingconfigured to be at least partially disposed within the sheath lumen.28. The method of claim 21, wherein the rotational atherectomy devicefurther comprises a fluid impermeable membrane along the drive shaft andsurrounding an outer diameter of at least a portion of the drive shaft.29. The method of claim 21, wherein the fluid impermeable membranesurrounds the drive shaft extending between the first and secondstability elements.